In Konstant U.S. Pat. Nos. 4,773,546; 4,915,240; 4,982,851; and 5,080,241, as well as Konstant et al. U.S. Pat. No. 4,613,270, various rack systems are disclosed in which pairs of rails are provided for receiving rolling carts. Pallets for storing goods may be placed on the rolling carts, and then pushed rearwardly along a pair of rails to make room for another pallet to be placed in front. Thus, considerable space saving is achieved.
Such racks typically have many bays containing parallel tracks for storing many pallets in side-by-side relation. Additionally, the racks may be adapted for storing typically two to five pallets in linear array along the rails in a convenient manner so that the pallets may be retrieved, one by one, from the front of the rails, with the carts rolling forwardly toward the front when they are permitted to do so. Arrays of rails may be placed one above each other, with adequate spacing so that pallets may be inserted onto carts which are in rolling relation with various pairs of the rails. Thus a rack may be provided which has a very high storage volume and storage density of pallets, for use in a warehouse, with a reduction in the number of aisles.
The various rows of rails of such racks are carried on horizontal beams, which are typically perpendicular to the rails. It has been found that the front beam typically carries less of a load than does an inner beam, which is parallel to the front beam and typically spaced inwardly along the rails about the length of one pallet or more. Because of this, it has been generally desirable to use a heavier, stronger second beam, to reduce flex of the second beam in response to the heavier load.
In accordance with this invention, a rack such as a pallet rack is provided in which inner beams which are subjected to greater loads do not have to be made of heavier, stronger material, for a simplification of the construction of the rack and for a savings in cost. Nevertheless, undue flexing of a lighter beam can be avoided in the face of heavier loads, with cost savings.